As is known, polymerase chain reaction (PCR) is a biochemical technology wherein a specific region of a Deoxyribonucleic acid (DNA) strand (the DNA target) is amplified across several orders of magnitude to generate copies of a particular DNA sequence. PCR has become a common and indispensable technique used in medical and biological research labs for a variety of applications. However, the methods of isolating/preparing samples of the DNA target for PCR that are commonly in use are both time consuming and tedious.
Recent technological developments have accelerated the purification process. By way of example, Beebe et al., United States Patent Application Publication No. 2011/0213133, incorporated by reference herein in its entirety, discloses a device and a method for facilitating extraction of a fraction such as a DNA target from a biological sample. The biological sample includes non-desired material and a fraction-bound solid phase substrate. The device includes an input zone for receiving the biological sample therein and a phase-gate zone for receiving an isolation buffer therein. An output zone receives a reagent therein. A force is movable between a first position adjacent the input zone and a second position adjacent the output zone. The force urges the fraction-bound solid phase substrate from the input zone, through the phase-gate zone and into the output zone.
While functional for its intended purpose, the Beebe et al., '133 publication does not contemplate a specific structure for integrating the device disclosed therein with instruments, such as PCR machines, light cyclers, or thermocyclers, for downstream analysis. Current methods of integration involve transferring the DNA target via pipetting to a tube, strip tubes, or a well plate which is compatible with the plethora of instruments available for downstream analysis and processing. It can be appreciated that it would be highly desirable to provide a device that directly integrates with existing tubes, strip tubes, and well plates and that streamlines the process for transferring the DNA target from the device disclosed in the Beebe et al., '133 publication (as well as, similar type devices) to the various instruments currently available for downstream analysis.
Therefore, it is a primary object and feature of the present invention to provide a device and a method for transferring a target between locations.
It is a further object and feature of the present invention to provide a device and a method for transferring a target that allows for the simple integration of a microfluidic device with instruments, such as PCR machines, light cyclers, mass spectrometers, spectrophotomers, or thermocyclers, for downstream analysis.
It is a still a further object and feature of the present invention to provide a device and a method for transferring a target between locations which is simple to use and inexpensive to manufacture.
In accordance with the present invention, a device is provided for transferring a target from a first location to a second location. The target is bound to solid phase substrate to form a target bound solid phase substrate. The device includes a transfer surface having a first region for receiving the target bound solid phase substrate thereon for transfer. The transfer surface is movable between a first position wherein the transfer surface is aligned with the first location and spaced therefrom by a distance and a second position wherein the transfer surface is aligned with the second location. An alignment structure aligns the transfer surface with respect to the second fluid with the transfer surface in the second location. A force is movable between an attraction position wherein the target bound solid phase substrate are drawn toward the first region of the transfer surface and a discharge position wherein the target bound solid phase substrate are freed of the force. The force may be magnetic.
It is contemplated for a first fluid to be received in a sample container at the first location. The inner surface of the sample container can be hydrophobic which causes the first fluid in the sample container to have a non-concave meniscus. Alternatively, an insert may be receivable in the sample container along the inner surface thereof. The insert causes the first fluid in the sample container to have a non-concave meniscus. A second fluid may received in a receptacle at the second location.
The alignment structure includes a plate. The transfer surface extends along a first side of the plate and overlaps the upper edge of the receptacle with the transfer surface in the second position. In addition, the alignment structure may include a wall depending from the transfer surface. The wall may have an inner surface that defines the first region of the transfer surface and an outer surface engageable with the inner surface of the receptacle with the transfer surface in the second position. The alignment structure may also include a second wall depending from the transfer surface. The second wall has an inner surface engageable with the outer surface of the receptacle with the transfer surface in the second position and an outer surface. Alternatively, an inner surface of the wall depending from the transfer surface may be engageable with the outer surface of the receptacle with the transfer surface in the second position and an outer surface. The first region of the transfer surface may include a pinning element extending about the outer periphery thereof. The pinning element retains transfer fluid in the first region of the transfer surface. The plate includes an upper surface on a second side thereof. The force is adjacent the upper surface of the plate with the force in the attraction position.
In an alternate embodiment, the alignment structure may include a plate and a transfer element depending a first side thereof. The transfer element terminates at the transfer surface and has an outer surface engageable with the inner surface of the receptacle with the transfer surface in the second position. In addition, the first side of the plate is engageable with the upper edge of the receptacle with the transfer surface in the second position.
An intermediate fluid may be disposed between the transfer surface and the first location. In such arrangement, the target bound solid phase substrate passes through the intermediate fluid as the target bound solid phase substrate are drawn from the first location to the first region of the transfer surface.
In accordance with a further aspect of the present invention, a device is provided for transferring a target from a first fluid at a first location to a second location. The target is bound to solid phase substrate to form target bound solid phase substrate. The device includes a means for forming a non-concave meniscus with the first fluid. A transfer region receives the target bound solid phase substrate for transfer. The transfer region is movable between a first position wherein the transfer region is aligned with the meniscus of the first fluid and spaced therefrom and a second position wherein the transfer region is aligned with the second location. An alignment structure aligns the transfer region with respect to the receptacle with the transfer region in the second position. A force is movable between an attraction position wherein the target bound solid phase substrate are drawn toward the first region of the transfer surface and a discharge position wherein the target bound solid phase substrate are freed of the force.
The first fluid may be received in a sample container. The forming means may include an inner surface of the sample container being hydrophobic, thereby causing the first fluid in the sample container to have the non-concave meniscus. Alternatively, forming means may including an insert receivable in the sample container along the inner surface thereof. The insert causes the first fluid in the sample container to have the non-concave meniscus.
An intermediate fluid may be disposed between the transfer region and the first fluid. The target bound solid phase substrate passes through the intermediate fluid as the target bound solid phase substrate are drawn from the first fluid to the transfer region.
The alignment structure includes a plate and receptacle is provide at the second location. The transfer region extends along a first side of the plate and the plate overlaps the upper edge of the receptacle with the transfer region in the second position. The alignment structure may also include a wall depending from the transfer first side of the plate. The wall is engageable with the receptacle with the transfer region in the second position. Transfer fluid may be provided at the transfer region and a pinning element may extend about the outer periphery of the transfer region. The pinning element retains the transfer fluid in the transfer region.
In accordance with a further aspect of the present invention, a method is provided for transferring a target from a first fluid at a first location to a second location. The target is bound to solid phase substrate to form target bound solid phase substrate. The method includes the steps of forming a non-concave meniscus with the first fluid and drawing the target bound solid phase substrate from the first fluid into a transfer region of a transfer device. The transfer region is aligned with the second fluid. The target bound solid phase substrate is released and passes to the second location.
The step of forming the non-concave meniscus with the first fluid may include the additional steps of depositing the first fluid in a sample container and inserting an insert into the sample container, the insert causing the first fluid in the sample container to form the non-concave meniscus. Alternatively, the step of forming the non-concave meniscus with the first fluid may include the additional step of depositing the first fluid in a sample container having a hydrophobic inner surface. The hydrophobic inner surface causes the first fluid in the sample container to form the non-concave meniscus. It is contemplated to position an intermediate fluid between the first fluid and the transfer region, and pass the target bound solid phase substrate through the intermediate fluid as the target bound solid phase substrate are drawn from the first fluid to the transfer region.